To date, millions of tooth whitening kits have been sold across the world to consumers seeking to brighten their smiles. Tooth whitening products can be applied as paint-on gels, strips, or mouth guards, either at the dentist’s office or at home. The whitening ingredient in these products is hydrogen peroxide. In general, the more hydrogen peroxide, the greater the whitening power. Toothpastes and mouth rinses may also contain low concentrations of hydrogen peroxide as a disinfectant to prevent plaque and inflammation of the gums. Are toothpastes, mouth-rinses and tooth whitening products containing hydrogen peroxide safe? Should they be freely available to consumers?

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Source document:
Tooth Whiteners & Oral SCCP (2007)
Hygiene Products Summary & Details:
GreenFacts (2008)
containing hydrogen peroxide
Hydrogen Peroxide
Context - To date, millions of tooth
whitening kits have been sold across the 1. What is hydrogen peroxide and what is it
world to consumers seeking to brighten used for? .............................................3
their smiles. Tooth whitening products 2. What health effects of hydrogen peroxide
can be applied as paint-on gels, strips, have been observed?.............................3
or mouth guards, either at the dentist’s
Oral hygiene products & tooth whiteners
office or at home. The whitening
ingredient in these products is hydrogen 3. How is hydrogen peroxide used to whiten
peroxide. In general, the more hydrogen teeth?..................................................4
peroxide, the greater the whitening 4. How much hydrogen peroxide is an individual
power. exposed to when using dental products?...4
5. Can tooth whitening products containing
Toothpastes and mouth rinses may also
hydrogen peroxide harm teeth? ..............4
contain low concentrations of hydrogen
6. How safe are products containing hydrogen
peroxide as a disinfectant to prevent
peroxide?.............................................5
plaque and inflammation of the gums.
7. What should be considered before a tooth
Are toothpastes, mouth-rinses and tooth whitening treatment?.............................5
whitening products containing hydrogen 8. Conclusion – Are oral hygiene products and
peroxide safe? Should they be freely tooth whiteners containing hydrogen peroxide
available to consumers? safe and should they be freely available to
consumers?..........................................6
An assessment by the European
Commission Scientific Committee on
Consumer Products (SCCP)
The answers to these questions are a faithful summary of the scientific opinion
produced in 2007 by the Scientific Committee on Consumer Products (SCCP):
"Opinion on Hydrogen peroxide, in its free form or when released, in oral hygiene products and tooth whitening
products"

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The full publication is available at: http://copublications.greenfacts.org/en/tooth-whiteners/
and at: http://ec.europa.eu/health/opinions/en/tooth-whiteners/
This PDF Document is the Level 1 of a GreenFacts Co-Publication. GreenFacts Co-Publications are published
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1. What is hydrogen peroxide and what is it used for?
Hydrogen peroxide is a highly reactive chemical containing hydrogen
and oxygen. It is used mainly in the production of other chemicals
and to bleach paper and textiles. Moreover, contact lenses can be
disinfected with highly diluted hydrogen peroxide.
Hydrogen peroxide is
Carbamide peroxide is a chemical that is made of hydrogen peroxide used in some toothpastes,
mouth rinses and tooth
and urea. whitening products
Source: Sergei Krassii
Both hydrogen peroxide and carbamide peroxide are used in cosmetics, mainly as bleaches
in dental products such as tooth whiteners and some hair products. Low concentrations
may also be used in toothpastes and mouth rinses as a disinfectant to prevent plaque and
inflammation of the gums.
In the European Union, cosmetics are regulated by the Cosmetics Directive
2. What health effects of hydrogen peroxide have been observed?
2.1 Swallowing a large dose of hydrogen peroxide can be lethal to
humans.
2.2 Highly diluted hydrogen peroxide solutions are non-irritant or
mildly irritant. However, animal tests have shown that, when The use of contact lens
exceeding certain concentrations, hydrogen peroxide can cause solutions containing some
hydrogen peroxide can
irritation of eyes, skin, and the inside of mouth, stomach, and irritate the eyes
intestine. The use of eye drops and contact lens solutions containing Source: Free Software
Foundation
some hydrogen peroxide can irritate the eyes. Hydrogen peroxide
is not considered to cause allergic reactions of the skin.
2.3 To test whether repeated exposure to hydrogen peroxide can harm health, mice and
rats were given hydrogen peroxide solutions by various means. Above certain exposure
levels, effects on body weight, blood and some organs were seen. Risks to humans can be
assessed by comparing human exposures to the highest exposure at which no harmful
effects were observed in any animal studies.
2.4 Hydrogen peroxide can act as a weak cancer promoter, meaning it can slightly stimulate
the growth or multiplication of cancer cells. There is not enough data to evaluate potential
effects of hydrogen peroxide on reproduction and development.
2.5 People with certain genetic disorders are more vulnerable to hydrogen peroxide because
their bodies cannot break it down effectively.

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3. How is hydrogen peroxide used to whiten teeth?
Tooth whiteners and oral hygiene products – such as certain
toothpastes and mouth rinses – use hydrogen peroxide or carbamide
peroxide for its whitening and/or disinfecting properties. Peroxide
whitens teeth by passing into the tooth and reacting with the
molecules that cause stains or discoloration. In general, the more
Tooth whiteners can be
peroxide, the greater the whitening power. applied to teeth using
custom made
mouthguards
Depending on their peroxide content, such products are either freely Source: GreenFacts
sold over the counter for home use, dispensed by dentists for home use, or exclusively
applied by dentists in their offices. In the European Union, oral hygiene products may only
be sold freely to consumers if they contain no more than 0.1% hydrogen peroxide whereas
in the USA, whitening products are sold at higher concentrations. In-office bleaching generally
uses products with higher levels of whitening agents.
Tooth whitening products can be applied at home in three different ways: using strips that
are stuck onto teeth, custom made mouthguards that maintain the whitening product on
the teeth, or gels that are painted directly on the teeth.
The length of treatment depends on the level of discoloration and the whitening product
used. It ranges from short interventions in the dental office to applications at home lasting
minutes/hours per day and repeated over a number of days.
4. How much hydrogen peroxide is an individual exposed to when using
dental products?
4.1 Toothpastes and mouth rinses may also contain low concentrations of hydrogen peroxide
as a disinfectant to prevent plaque and inflammation of the gums. Studies have shown that
hydrogen peroxide from toothpastes or mouth rinses is rapidly broken down in the mouth
by the saliva, but some of it is swallowed. Toothpastes and mouth rinses that contain small
amounts of hydrogen peroxide and are used once or twice per day do not seem to harm
the inside of the mouth ,when used up to 6 months for toothpastes or 24 months for mouth
rinses. However, rinses that contain larger amounts of hydrogen peroxide or that are used
more frequently can cause mouth irritation.
4.2 How much hydrogen peroxide is released into the saliva during tooth whitening
treatments depends mostly on the amount of hydrogen peroxide in the product being used
and the product type and only partly on the amount of saliva produced.
During a tooth whitening treatment procedure, the concentration of hydrogen peroxide on
the gums and in the saliva falls rapidly because hydrogen peroxide is broken down quickly.
It is estimated that up to 25% of the hydrogen peroxide applied by tooth whitening products
is swallowed.
5. Can tooth whitening products containing hydrogen peroxide harm teeth?
5.1 The two most common side effects of using tooth whitening products containing
hydrogen peroxide are mouth irritation and increased tooth sensitivity to temperature
changes. Both effects are temporary. No information is available on long-term effects of
the use of tooth whitening products or on the effects of repeated use of such products.

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5.2 Hydrogen peroxide passes easily through the tooth enamel.
According to most existing studies, bleaching does not harm the enamel.
However, a few investigations have reported that bleaching can harm
the surface of the teeth, making the enamel more porous and leading
to dents, scratches, and loss of minerals.
5.3 After crossing the enamel, hydrogen peroxide passes into dentin
and pulp. In some cases, whiteners cause minor inflammations of the
pulp, which might be the reason for the increased tooth sensitivity that
sometimes occurs. However, generally, tooth whitening does not seem According to most
studies, tooth
to harm dental pulp of healthy teeth, possibly because the levels of whitening does not
hydrogen peroxide are too low to cause damage. harm the enamel
5.4 Tooth whitening does not usually change the colour of fillings and other restorative
materials. It does not affect porcelain, other ceramics, or dental gold. However, it can
slightly affect restorations made with composite materials, cements and dental amalgams.
6. How safe are products containing hydrogen peroxide?
6.1 Solutions containing more than 5% hydrogen peroxide are labelled “harmful” and
“irritating to eyes”. At higher concentrations other mentions are added, highlighting the
risk of serious damage to eyes, irritation of the respiratory system and skin, and burns.
6.2 Oral hygiene products and tooth whiteners containing hydrogen peroxide are not very
likely to affect the body as a whole, because the substance is rapidly broken down. But
above certain levels effects have been seen in animals. In addition, there are concerns
about direct effects like irritation in the mouth and in the gastrointestinal system after
swallowing.
In the European Union, oral hygiene products may only be sold freely to consumers if they
contain no more than 0.1% hydrogen peroxide.
Risks to humans can be estimated based on animal studies. For general effects on the body,
the margin of safety is considered sufficient if human exposures are at least 100 times
lower than the level at which no effects have been observed in any animal study. This is
the case for toothpastes and mouth rinses containing 0.1% of hydrogen peroxide and tooth
whitening products containing 6% of hydrogen peroxide, but not for tooth whitening products
containing more hydrogen peroxide.
7. What should be considered before a tooth whitening treatment?
Above 0.1% hydrogen peroxide, tooth bleaching is not just a simple
cosmetic procedure. Dentists should diagnose the cause of the
staining, check whether patients have any other oral health problems,
and counsel patients about the best way of dealing with this
esthetical problem. Before engaging in tooth
whitening treatment, a
dentist should be
As already mentioned above, common undesirable side effects of consulted
tooth whitening treatment, such as increased tooth sensitivity and Source: StockXpert
mouth irritation, usually disappear within a few days. The surface of fillings and other
restorations can be affected.

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Hydrogen peroxide can act as a weak cancer promoter, meaning it can slightly stimulate
the growth or multiplication of cancer cells. Tobacco use, alcohol abuse, and specific genetic
predispositions increase the risk of oral cancer. Hydrogen peroxide may therefore further
increase this risk, especially when the treatment is repeated. This may be of concern as
smokers are likely candidates for tooth whitening. The risk of harmful effects may be greater
for people who have pre-existing oral diseases.
8. Conclusion – Are oral hygiene products and tooth whiteners containing
hydrogen peroxide safe and should they be freely available to consumers?
To conclude, the SCCP (Scientific Committee on Consumer Products) of the European
Commission expressed the following opinions:
• The use of toothpastes, mouth rinses and tooth whiteners containing up to
0.1% hydrogen peroxide does not pose a risk to the health of the consumer.
Toothpastes and mouth rinses should not contain more than 0.1% hydrogen
peroxide.
• The use tooth whitening products containing 0.1 to 6 % hydrogen
peroxide entails potential risks for the consumer. These risks increase with
increasing concentration of hydrogen peroxide and frequency of application.
Potential risks of the use of tooth whiteners containing between 0.1 and 6 %
hydrogen peroxide can be limited if tooth whitening is done properly with the
approval and under the supervision of a dentist. The specific situation of each
individual should be taken into account prior to treatment.
Additional research is needed on the use of tooth whitening products over longer
time periods.
• Use of tooth whitening products containing more than 6% is not considered
safe for use by consumers.

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